Page 5 of 5 FirstFirst 12345
Results 41 to 46 of 46

Thread: The chemistry of the glycerol (and soap) phase

  1. #41
    Join Date
    Nov 2010
    Location
    Fort Worth, Texas, USA
    Posts
    303

    Re: The chemistry of the glycerol (and soap) phase

    smithy: The equilibrium Dr Mark refers to is calculated mathmatically by multiplying the concentration of the products of a reaction divided by the concentration of the reactants of a reaction. This was used in calculatiion of the strength of weak acids like vinegar or weak bases like ammonia gas dissolved in water. But the equilibrium of methoxide a strong base has methanol as a solvent and water is a product of the reaction. It's a different approach to an equilibrium equation. With weak acids and bases the concentration of water (the solvent) is ignored. The concentration of products (pH) with weak acids and bases is very small. But Dr Mark's proceedure of removing water in the production of methoxide with calcium oxide or cement complicates the equation. The methoxide concentration may be much higher. Maybe Dr Mark can say how to figure the equilibrium constant product in the case since we were given the concentration of the reactants and products at 25 degrees centigrade by Tony. The water present in potassium hydroxide does affect the concentration of methoxide. I vaccum distilled water out of potassium hydroxide solid. I damaged expensive equipment distilling out water from potassium hydroxide solid because it was so hot, over 200 Degrees centigrade.
    Last edited by WesleyB; 22nd May 2019 at 11:26 AM.

  2. #42
    Join Date
    Oct 2011
    Location
    Perth
    Posts
    225

    Re: The chemistry of the glycerol (and soap) phase

    Quote Originally Posted by WesleyB View Post
    What information do I get from the graph? It looks like as the methoxide concentration at 25 degrees centigrade increases so does the water. I don't know the units used in the graph, under magnification they are unclear. I seems to indicate 2% of something being the concentration. Your method of posting information might be improved. As the methoxide concentration increases the water concentration increases and water decomposes the methoxide. The information under magnification is unclear.
    Yes - my apologies - the thumbnails aren't much use and despite my best efforts I just cannot work out how to post the images on my desktop onto this site. The method works for other images, but not for the images I'm attempting to post from from my image hosting account. Hopefully the administrator can help me
    Y

  3. #43
    Join Date
    Oct 2011
    Location
    Perth
    Posts
    225

    Re: The chemistry of the glycerol (and soap) phase

    Quote Originally Posted by Tony From West Oz View Post
    Mark, Can you please confirm my calculations of the Molar weights of the reactants?
    Is the molar weight of KOH (K (40) + O (16) + H (1)) 57?
    Is the molar weight of CH3OH (C (12) + H *4 (4) + O (16)) 32?

    I was hoping that you would have provided me some guidance in this, as I only have lower school chemistry education.
    It appears to me that the way to calculate the molar weight ratios of the reactants is to sum the molecular weights of the elements in the molecules. Thus the relative weights of the reactants relate directly to the formula. If this is correct then the relative mass of the reaction products can easily be calculated, by reference to the graph.
    If this is not how to calculate the molar weight ratios, then please educate me how they should be calculated.

    thanks in advance,
    Tony
    Yes, quite correct. I'll talk you through the processes involved just as soon as I work out how to post the images on my desktop onto this site

  4. #44
    Join Date
    Oct 2011
    Location
    Perth
    Posts
    225

    Re: The chemistry of the glycerol (and soap) phase

    Quote Originally Posted by WesleyB View Post
    smithy: The equilibrium Dr Mark refers to is calculated mathmatically by multiplying the concentration of the products of a reaction divided by the concentration of the reactants of a reaction. This was used in calculatiion of the strength of weak acids like vinegar or weak bases like ammonia gas dissolved in water. But the equilibrium of methoxide a strong base has methanol as a solvent and water is a product of the reaction. It's a different approach to an equilibrium equation. With weak acids and bases the concentration of water (the solvent) is ignored. The concentration of products (pH) with weak acids and bases is very small. But Dr Mark's proceedure of removing water in the production of methoxide with calcium oxide or cement complicates the equation. The methoxide concentration may be much higher. Maybe Dr Mark can say how to figure the equilibrium constant product in the case since we were given the concentration of the reactants and products at 25 degrees centigrade by Tony. The water present in potassium hydroxide does affect the concentration of methoxide. I vaccum distilled water out of potassium hydroxide solid. I damaged expensive equipment distilling out water from potassium hydroxide solid because it was so hot, over 200 Degrees centigrade.
    Quite correct but the whole point of my method is that all water from all sources is removed. So whatever water is present in the KOH is removed by the drying agent. I'll put up some calculations once I can figure out how to post images
    Q

  5. #45
    Join Date
    Jan 2006
    Location
    ลึก ประเทศอินเด&
    Posts
    2,102

    Re: The chemistry of the glycerol (and soap) phase

    Hi Mark,

    Quote Originally Posted by Mark View Post
    Quite correct but the whole point of my method is that all water from all sources is removed.
    An inaccurate statement. Even if your method does remove all the water produced when making methoxide, and you have never shown any testing to support this claim, you keep omitting to take into account the water that WILL be present in the oil.


    whatever water is present in the KOH is removed by the drying agent.
    You say the water is removed, however you have never provided any testing to show this is actually what happens.
    You also say the normal method of making biodiesel requires heat and will not proceed at room temperature and we all know this is not true. You did not even perform a simple 15 minute test to verify this most important fact.
    More importantly you continue to ignore research papers and experiments performed by people on this forum that shows the standard base method of making biodiesel works fine at room temperature.
    You also claimed that the FFA content of the oil does not matter and that is not true either.

    When you did your two degrees in chemistry that you are clearly so proud of, did they teach you that once you have a degree in chemistry you know everything and do not need to perform any experimentation in support of your claim and to ignore all valid information that does not support your claim?



    I'll put up some calculations once I can figure out how to post images
    It would be a whole lot more meaningful if you actually did some testing and posted some test results.

    Last edited by tillyfromparadise; 22nd May 2019 at 06:56 PM.

  6. #46
    Join Date
    Jan 2006
    Location
    ลึก ประเทศอินเด&
    Posts
    2,102

    Re: The chemistry of the glycerol (and soap) phase

    Hi Mark,
    Quote Originally Posted by Mark View Post

    At last I've figured out how to post figures. The URL bit still isn't working that I can see, but the thumbnails will do for now.

    Right let's go through this step by step.

    Firstly, here is the methoxide equilibrium, exactly as I wrote it in my posts

    Attachment 2314
    Here is the full size version. This did take a good 10 seconds to figure out how to do.






    Now lets look at Figure 1:

    What information do you get from this?

    Attachment 2315
    And the second thumbnail in full size



    If you require any further help with this do not hesitate to ask
    Last edited by tillyfromparadise; 23rd May 2019 at 01:09 PM.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •